绿茶表没食子儿茶素没食子酸酯对β淀粉样蛋白25-35诱导小鼠神经瘤母细胞N2a损伤的神经保护作用及其机制  

Neuroprotective effect of epigallocatechin-3-gallate on injury of mouse neurocytoma N2a cells induced by beta-amyloid 25-35 and relevant mechanism

作　　者：唐玲[1] 唐荣伟[1] 刘佳[1] 祝瑜[1] TANG Ling, TANG Rong-wei, LIU Jia, ZHU Yu(Department of Clinical Medicine, Dazhou Vocational and Technical College, Dazhou 635001, Sichuan Province, Chin)

机构地区：[1]达州职业技术学院临床医学系,四川达州635001

出　　处：《中国生物制品学杂志》2018年第3期262-267,共6页Chinese Journal of Biologicals

摘　　要：目的探讨绿茶表没食子儿茶素没食子酸酯(green tea epigallocatechin-3-gallate,EGCG)对β淀粉样蛋白25-35(beta-amyloid 25-35,Aβ_(25-35))诱导的小鼠神经瘤母细胞N2a损伤的神经保护作用及其机制。方法体外培养N2a细胞,用含50μg/m L水溶性Aβ_(25-35)片段的DMEM培养液作用于N2a细胞后,加入不同浓度的EGCG(5、10、20、40μmol/L)作用不同时间(24、48、72 h),同时设模型组(未用EGCG处理)及DMSO组(仅用0.1%的DMSO处理)。MTT法检测EGCG对N2a细胞存活率的影响;JC-1法检测EGCG对线粒体膜电位的影响;半胱氨酸蛋白酶-3(caspase-3)活性检测试剂盒检测EGCG对N2a细胞中caspase-3活性的影响;Western blot法检测EGCG对N2a细胞内Bax、Bcl-2和caspase-3蛋白表达水平的影响。结果与模型组和DMSO组比较,20和40μmol/L的EGCG作用24 h时,N2a细胞存活率及caspase-3酶活性明显降低(P<0.05),A_(590)/A_(530)值显著升高(P<0.05);20μmol/L的EGCG作用24 h时,N2a细胞中Bax和caspase-3蛋白表达水平均明显降低(P<0.05),Bcl-2蛋白水平明显升高(P<0.05)。结论 EGCG对Aβ_(25-35)诱导的N2a细胞的损伤具有保护作用,其机制可能与EGCG调控细胞凋亡相关蛋白Bax、Bcl-2和caspase-3的表达水平有关。Objective To investigate the neuroprotective effect of epigallocatechin-3-gallate（EGCG）on injury of mouse neurocytoma N2a cells induced by beta-amyloid 25-35（Aβ_（25-35））as well as the relevant mechanism.Methods N2a cells were cultured in vitro and treated with DEME containing 50μg/m L water-soluble Aβ_（25-35）,then with various concentrations（5,10,20,40μmol/L）of EGCG for 24,48 and 72 h separately,using those untreated with EGCG and those treated only with 0.1%DMSO as controls.The survival rate of injured N2a cells was measured by MTT assay,while the mitochondrial membrane potential by JC-1 staining,and the capase-3 activity by caspase-3 activity kit.The expression levels of Bax,Bcl-2 and caspase-3 proteins in N2a cells were determined by Western blot.Results Compared with those untreated with EGCG and those treated only with 0.1%DMSO,both survival rate and caspase-3 activity of N2a cells after treatment with 20 and 40μmol/L EGCG for 24 h decreased significantly（P 〈0.05）,while the A_（590）/A_（530）increased significantly（P 〈0.05）.However,both the expression levels of Bax and caspase-3 proteins in N2a cells after treatment with 20μmol/L EGCG for 24 h decreased significantly（P 〈0.05）,while that of Bcl-2 protein increased significantly（P 〈0.05）.Conclusion EGCG plays a neuroprotective role in the injury of N2a cells induced by Aβ_（25-35）by a possible mechanism of regulating the expression levels of cell apoptosis-associated Bax,Bcl-2 and caspase-3 proteins.

关 键 词：绿茶表没食子儿茶素没食子酸酯 Β淀粉样蛋白 小鼠神经瘤母细胞N2a 神经保护作用 

分 类 号：Q26[生物学—细胞生物学] R739.42[医药卫生—肿瘤]